The present invention relates to diene elastomer compositions usable in particular for the manufacture of tyres or semi-finished products for tyres, for example of treads for these tyres.
It also relates to reinforcing fillers capable of reinforcing such rubber compositions, more particularly to reinforcing fillers of organic or polymeric type, and also to their use for reinforcing such rubber compositions.
So as to reduce fuel consumption and the pollution emitted by motor vehicles, major attempts have been made by tyre designers to obtain tyres having all of the following: very low rolling resistance, improved adhesion both on dry ground and on wet or snow-covered ground, and good wear resistance. One effective solution to this problem has been found, over the last fifteen years, owing to the development of new rubber compositions comprising truly reinforcing fillers of inorganic type, also known as “non-black fillers”, very particularly highly dispersible silicas (“HD” silicas), which have proved capable of replacing conventional carbon blacks for tyres in their reinforcing filler function.
However, these reinforcing inorganic fillers, due to having a slightly greater density for an equivalent reinforcing ability, have the known drawback of increasing the weight of the compositions and articles made of rubber derived therefrom, compared with the use of carbon black, which rather rules out another, more general, object, which is to reduce the weight of the tyres and therefore of the vehicles comprising them.
In continuing their research, the Applicants have discovered that there are certain synthetic organic fillers which can be used in these compositions as true reinforcing fillers, that is to say, are capable of replacing conventional carbon blacks for tyres just like HD silicas.
These synthetic organic fillers, due to having a density which is approximately half as much, make it possible very significantly to reduce the weight of the compositions and that of the rubber articles containing them, without compromise on the use properties of the tyres.